Vacuum cleaner equipped with suction relief nozzle assembly

ABSTRACT

A vacuum cleaner includes a body having a canister assembly and a nozzle assembly. A suction generator and dirt collection vessel are carried on the body. Further the nozzle assembly includes a housing including a bottom plate and an agitator cavity. A rotary agitator is held in the agitator cavity. A suction relief inlet is provided in the housing above the bottom plate. A passageway is also provided for directing air from the suction relief inlet to the agitator cavity adjacent the bottom plate.

This utility patent application claims the benefit of priority in U.S. Provisional Patent Application Ser. Nos. 61/900,073 filed on Nov. 5, 2013; 61/941,110 filed on Feb. 18, 2014; and 61/972,544 filed on Mar. 31, 2014, the entirety of all disclosures of which are incorporated herein by reference.

TECHNICAL FIELD

This document relates generally to the floor care equipment field and, more particularly, to a vacuum cleaner equipped with a suction relief nozzle assembly which maintains proper airflow through the suction inlet of the vacuum cleaner even when the base plate of the nozzle assembly is sealed around the agitator cavity inlet opening by an underlying carpet or other surface being cleaned.

BACKGROUND

Floor care cleaning equipment such as central vacuum cleaners, canister vacuum cleaners and upright vacuum cleaners have long been known in the art. Such vacuum cleaners incorporate a fan and motor assembly that generates negative air pressure to draw dirt and debris into the vacuum cleaner. Many incorporate a nozzle assembly equipped with a rotary agitator that beats dirt and debris from the nap of an underlying carpet or rug in order to provide additional cleaning action. Entrained dirt and debris are removed from the airstream and collected in a dirt collection vessel such as a dirt cup or dust bag constructed of porous filter material. Some vacuum cleaners rely strictly upon bags or filters to clean dirt and debris from the airstream while others also utilize cyclonic airflow principles.

At certain times during operation, the bottom plate of the nozzle assembly may have a tendency to seal against the surface being cleaned thereby restricting airflow through the vacuum cleaner. This compromises cleaning efficiency and generates excessive intra-nozzle suction making it very difficult to push and pull the vacuum cleaner nozzle back-and-forth across the surface being cleaned. This document relates to a vacuum cleaner equipped with a suction relief valve to maintain proper airflow through the vacuum cleaner for maximum cleaning efficiency, while preventing the bottom plate from sealing against the surface being cleaned. In this way the new vacuum cleaner affords easy push/pull of the nozzle assembly.

SUMMARY

In accordance with the purposes and benefits described herein, a vacuum cleaner is provided comprising a body including a canister assembly and a nozzle assembly. A suction generator and a dirt collection vessel are both carried on that body. Further the nozzle assembly includes (a) a housing including a bottom plate and a suction cavity; (b) a suction relief inlet provided in the housing above the bottom plate; and (c) a passageway for directing air from the suction relief inlet to the suction cavity adjacent the bottom plate.

The vacuum cleaner further includes an airflow control valve for controlling the flow of air through the suction relief inlet. In at least one embodiment the suction relief inlet comprises a right side inlet on a right side of the housing and a left side inlet on a left side of the housing. More specifically, the airflow control valve comprises a first flexible and resilient flap internal to and covering the right side inlet and a second flexible and resilient flap internal to and covering the left side inlet. The two flaps are normally biased into a closed position but are displaced into an open position when the bottom plate seals against an underlying carpet or surface to be cleaned. This serves to relieve excessive intra-nozzle suction, allowing the nozzle assembly to be easily pushed and pulled back-and-forth across the carpet or surface being cleaned.

In one possible embodiment, the suction cavity comprises an agitator cavity. Further, the vacuum cleaner includes (a) a rotary agitator disposed in the agitator cavity and (b) an agitator cavity shield between the housing and the agitator. The passageway is formed between the outer surface of this agitator cavity shield and an inner surface of the housing. The passageway directs air from the suction relief inlets, ideally to the outer perimeter of the agitator cavity at a level even with or optimally and minimally just above the bottom plate.

In addition the agitator cavity shield includes a first recess at a right end and a second recess at a left end to direct airflow from the suction relief inlet toward the right and left ends of the agitator cavity. A blocking rib or air diversion channel is provided adjacent a lowermost and forwardmost edge of the agitator cavity shield for directing air toward the right and left ends of the agitator cavity. In addition the agitator cavity shield is tapered at a forward edge at the right and left ends so as to form a split discharge outlet of the passageway adjacent the ends of the agitator cavity immediately above the bottom plate whereby air from the suction relief inlet passes through the passageway and is discharged from the split discharge outlet adjacent the left and right ends of the agitator cavity so that air sweeps across the entire effective width of the agitator cavity beneath the agitator toward a centerline of the nozzle assembly to provide enhanced cleaning action.

In the following description, there are described several preferred embodiments of the vacuum cleaner. As it should be realized, the vacuum cleaner is capable of other, different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the vacuum cleaner as set forth and described in the following claims. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated herein and forming a part of the specification, illustrate several aspects of the vacuum cleaner and together with the description serve to explain certain principles thereof. In the drawings:

FIG. 1 is a perspective view of a canister vacuum cleaner equipped with a nozzle assembly incorporating a suction relief valve.

FIG. 2 is a partially exploded perspective view of the nozzle assembly of that canister vacuum cleaner.

FIG. 3 is a partially exploded detailed view of the upper housing and the airflow control valves of that nozzle assembly.

FIG. 4 is a schematical view illustrating with action arrows the flow of air through the suction relief inlets and along a passageway between the upper housing (not shown for clarity) and the agitator cavity shield toward the agitator cavity of the nozzle assembly.

FIG. 5 is a cross-sectional view also illustrating the flow of air illustrated in FIG. 4.

FIG. 6 is a schematical view illustrating the flow of air through the agitator cavity after exiting the passageway in the front of the nozzle assembly (agitator cavity shield not shown for clarity).

FIG. 7 is a perspective view of an upright vacuum cleaner equipped with a nozzle assembly having a suction relief/airflow control valve system as described in this document.

Reference will now be made in detail to the present preferred embodiments of the vacuum cleaner, examples of which are illustrated in the accompanying drawings.

DETAILED DESCRIPTION

Reference is now made to FIG. 1 illustrating a canister vacuum cleaner 10 that has a canister assembly 12 that houses a suction generator and supports a dirt collection vessel 14. The vacuum cleaner 10 also includes a nozzle assembly 16 that is connected by means of a swivel 18 to a cleaning wand 20 connected to a control handle 22. A flexible hose 24 connects the control handle 22 to the canister assembly 12. In operation, dirt and debris are drawn into the nozzle assembly 16 and through the wand 20, control handle 22 and flexible hose 24 into the inlet 26 of the canister assembly 12. Dirt and debris are separated from the airstream and held in the dirt collection vessel 14 before the suction generator exhausts the now clean air back into the environment.

As illustrated in FIG. 2, the nozzle assembly 16 includes a housing comprising a base portion 28 and a cover 30. The base portion 28 holds various components of the nozzle assembly 16 including, for example, the agitator drive motor 32, the rotary agitator 34 and the agitator drive system including the agitation drive motor and the drive belt 36. An agitator cavity shield 38 is provided over the rotary agitator 34 between the housing base portion 28 and the housing cover 30.

As further illustrated in FIG. 5, the housing also includes a bottom plate 40 having an agitator cavity opening 42 that leads to the rotary agitator 34 disposed in the agitator cavity 44 defined between the agitator cavity shield 38 held in the housing base portion 28 and the bottom plate 40.

As further illustrated in FIGS. 2 and 5, two suction relief inlets 46 are provided at the right and left sides of the housing cover 30 above the bottom plate 40. Airflow control valves, generally designated by reference numeral 50, are provided in the suction relief inlets 46. As best illustrated in FIG. 3, each airflow control valve 50 comprises a main body 52 including a series of air inlets 54 and a cooperating flexible flap 56 sized and shaped to seat in the main body 52. More specifically, each flexible flap 56 includes a slot 58 that is received over a cooperating lug 60 projecting from the main body 52.

A latching element 62 secures the airflow control valve assemblies 50 together. More specifically, each latching element 62 includes opposed cooperating channels 64 that engage the margins of a cooperating notch 66 formed in the main body 52 as well as a slot 68 that is received over the lug 60 thereby capturing the flexible flap 56 between the latching element 62 and the main body 52. Similarly, each main body 52 includes opposed mounting channels 70 that engage the margin of the notches 72 formed in the housing cover 30. As further illustrated, the housing cover 30 includes a transparent cover insert 74 mounted in the opening 76. More specifically, fasteners in the form of screws 78 pass through the lugs 80 provided on the transparent cover insert 74 and through lugs 82 on the main bodies 52 and threadily engage screw bosses 84 on the cover housing 30 to secure the entire assembly together with the airflow control valve assemblies 50 held in the suction relief inlets 46 in the housing cover 30.

During normal vacuum cleaner operation, the flexible flaps 56 remain seated against the main bodies 52 closing the air inlets 54 and thereby preventing the passage of air through the airflow control valves 50. Thus, during normal vacuum cleaner operation, the suction generator draws all of the air running through the vacuum cleaner through the agitator cavity opening 42 in the bottom plate 40 into the suction inlet 86 at the rear of the agitator cavity 44.

Reference is now made to FIGS. 4-6 which illustrate the operation of the air flow control valves 50 when normal vacuum cleaner operation is not possible for some reason. For example, at certain times and under certain conditions, such as when vacuuming “super-soft” or “ultra-soft” carpet, the thick carpet pile P may effectively seal off the agitator cavity opening 42 in the bottom plate 40 thereby preventing the normal flow of air through the nozzle assembly 16. As the flow of air through the agitator cavity opening 42 decreases, the suction generator continues to draw a vacuum. As the negative pressure builds, the flexible flaps 56 are drawn away from the main bodies 52 and the airflow control valves 50 open. Air is then drawn through the air inlets 54 in the main bodies 52 of the airflow control valves 50 into the passageway 88 formed between (a) the inner surface of the housing cover 30 and transparent cover insert 74 and (b) the outer or upper surface of the agitator cavity shield 38. Here it should be noted that the agitator cavity shield 38 includes first and second recesses 90 (see FIG. 2) and a blocking rib or air diversion channel 92 that function together to direct air from the air inlets 54 through the passageway 88 toward the right and left ends of the agitator cavity 44. Note how the diversion channel 92 extends between the right and left recesses 90 on the agitator cavity shield 38 as illustrated in FIG. 2. Further, note how the blocking rib or air diversion channel 92 seals between the agitator cavity shield 38 and the front lip 94 of the housing base portion 28 in FIGS. 4 and 5 to prevent air flow through the passageway 88 along the middle portion of the agitator cavity shield between the recesses 90 thereby diverting all airflow from the air inlets 54 toward the right and left ends of the agitator cavity 44. This relief air breaks the seal between the bottom plate 40 and the surface being cleaned thereby relieving excessive suction and allowing one to easily push and pull the vacuum cleaner across the floor.

As further illustrated in FIGS. 4 and 6, the agitator cavity shield 38 is tapered at a forward edge at the right and left ends thereof so as to form a split discharge outlet 96. Together, the recesses 90, air diversion channel 92 and split discharge outlet 96 ensure that air being drawn into the nozzle assembly 16 through the airflow control valves 50 is delivered toward the outer ends of the agitator cavity 44 and imparted forward of the agitator 34 at the carpet/agitator interface for optimal cleaning. Accordingly, as illustrated in FIG. 6, the air then sweeps below the agitator 34 and across the entire effective width W of the nozzle assembly 16 as it travels from the split discharge outlet 96 through the agitator cavity 44 toward the centrally located suction inlet 86 (note action arrows B in FIG. 6). Such a path of movement ensures the most effective and efficient cleaning as dirt and debris across the entire width of the agitator 34 and agitator cavity 44 is swept into the suction inlet 86.

In summary, the vacuum cleaner 10 is equipped with airflow control valves 50 that provide numerous benefits and advantages. In the event the agitator cavity opening 42 in the bottom plate 40 becomes partially or fully sealed, the flexible flaps 56 of the valves 50 open allowing the suction generator to draw in air to facilitate easy push/pull and maintain optimum cleaning performance. This is ensured by the recesses 90, air diversion channel 92 and split discharge outlet 96 which function together to ensure that air being drawn from the valves 50 through the passageway 88 above the agitator cavity shield 38 is delivered toward the outer ends of the agitator 34 and agitator cavity 44. From there it sweeps across the agitator 34 and agitator cavity 44 toward the centrally located suction inlet 86 at the rear of the agitator cavity 44 to maximize the width of the airflow cleaning path and hence cleaning efficiency.

Up to this point, this document has only described and illustrated a canister vacuum cleaner. Reference is now made to FIG. 7 illustrating an upright vacuum cleaner 100 including an upper body assembly 102, holding a suction generator and dirt collection vessel (not shown), that is pivotally connected to a nozzle assembly 104 equipped with suction relief inlets 106 corresponding to the airflow control valves 50 described above with respect to the canister vacuum cleaner embodiment. The foregoing has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the vacuum cleaner to the precise form disclosed. Obvious modifications and variations are possible in light of the above teachings. For example, while a canister vacuum cleaner 10 and upright vacuum cleaner 100 have been illustrated and described, it should be appreciated that other, additional embodiments are contemplated and encompassed in the following claims. Such embodiments include a central vacuum cleaner system incorporating a nozzle assembly with the airflow control valves for suction relief purposes. Further, while the illustrated nozzle assembly 16 includes a rotary agitator 34 disposed in an agitator cavity 44, it should be appreciated that the nozzle assembly could include a simple suction cavity and no rotary agitator. Still further, while the illustrated airflow control valves 50 include resilient, flexible flaps 56 that respond to changes in suction pressure, it should be appreciated that the valves 50 may be spring-biased gate valves, plunger valves, shutter type valves or the like, wherein the spring element may be a compression, tension, torsion, leaf spring or other suitable design. Further, the valves may be electronic in nature, comprising electronic sensors and actuation mechanisms. Finally, it should be appreciated that all such modifications and variations are within the scope of the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled. 

What is claimed:
 1. A vacuum cleaner, comprising: a body including a canister assembly and a nozzle assembly; a suction generator carried on said body; and a dirt collection vessel carried on said body; said nozzle assembly including; (a) a housing including a bottom plate and a suction cavity; (b) a suction relief inlet provided in said housing above said bottom plate; and (c) a passageway for directing air from said suction relief inlet to said suction cavity adjacent said bottom plate.
 2. The vacuum cleaner of claim 1, further including an airflow control valve for controlling a flow of air through said suction relief inlet.
 3. The vacuum cleaner of claim 2, wherein said passageway directs air from said suction relief inlet toward opposing ends of said suction cavity.
 4. The vacuum cleaner of claim 2, wherein said suction relief inlet comprises a right side inlet on a right side of said housing and a left side inlet on a left side of said housing.
 5. The vacuum cleaner of claim 4, wherein said airflow control valve comprises a first flexible and resilient flap covering said right side inlet and a second flexible and resilient flap covering said left side inlet wherein said first and second flaps are normally biased into a closed position but are displaced into an open position when said bottom plate seals against an underlying carpet.
 6. The vacuum cleaner of claim 5, wherein said suction cavity comprises an agitator cavity and said vacuum cleaner further includes (a) a rotary agitator disposed in said agitator cavity and (b) an agitator cavity shield between said housing and said agitator, said passageway being formed between an outer surface of said agitator cavity shield and an inner surface of said housing.
 7. The vacuum cleaner of claim 6, wherein said agitator cavity shield includes a first recess at a right end and a second recess at a left end to direct airflow from said suction relief inlet toward right and left ends of said agitator cavity.
 8. The vacuum cleaner of claim 7, further including an airflow blocking rib between said agitator cavity shield and said cover for directing air from said suction relief inlet toward said right and left ends of said agitator cavity.
 9. The vacuum cleaner of claim 7, further including an air diversion channel adjacent a lowermost and forwardmost edge of said agitator cavity shield for directing air from said suction relief inlet toward said right and left ends of said agitator cavity.
 10. The vacuum cleaner of claim 9, wherein said air diversion channel extends between said first recess and said second recess.
 11. The vacuum cleaner of claim 10, wherein said agitator cavity shield is tapered at a forward edge at said right and left ends so as to form a split discharge outlet of said passageway adjacent each end of said agitator cavity immediately above said bottom plate whereby air from said suction relief inlet passes through said passageway and is discharged from said split discharge outlet adjacent left and right ends of said agitator cavity so that said air sweeps across an entire width of said agitator cavity toward a centerline of said nozzle assembly to provide enhanced cleaning action.
 12. The vacuum cleaner of claim 11, wherein said agitator cavity shield is transparent and said housing includes a transparent cover over said agitator cavity shield.
 13. The vacuum cleaner of claim 6, wherein said agitator cavity shield includes a right end channel and a left end channel for directing air from said suction relief inlet toward opposed ends of said agitator in said agitator cavity.
 14. The vacuum cleaner of claim 1, wherein said passageway directs air from said suction relief inlet toward opposing ends of said suction cavity.
 15. The vacuum cleaner of claim 1, wherein said suction relief inlet comprises a right side inlet on a right side of said housing and a left side inlet on a left side of said housing.
 16. The vacuum cleaner of claim 2, wherein said airflow control valve comprises a first flexible and resilient flap covering said right side inlet and a second flexible and resilient flap covering said left side inlet wherein said first and second flaps are normally biased into a closed position but are displaced into an open position when said bottom plate seals against an underlying carpet.
 17. The vacuum cleaner of claim 16, wherein said suction cavity comprises an agitator cavity and said vacuum cleaner further includes (a) a rotary agitator disposed in said agitator cavity and (b) an agitator cavity shield between said housing and said agitator, said passageway being formed between an outer surface of said agitator cavity shield and an inner surface of said housing.
 18. The vacuum cleaner of claim 17, wherein said agitator cavity shield includes a first recess at a right end and a second recess at a left end to direct airflow from said suction relief inlet toward right and left ends of said agitator cavity.
 19. The vacuum cleaner of claim 1, wherein said vacuum cleaner is a canister vacuum cleaner.
 20. The vacuum cleaner of claim 1, wherein said vacuum cleaner is an upright vacuum cleaner. 